Take a look at the article(s) that I wrote about the remote capablities of the CW Machine (I am the designer): http://www.eham.net/articles/23931
You will see that a delay of less than one character, and even of one character, will result in audible gaps in your transmission. Less than one character delay would require sending dits and dahs over the link, rather than complete characters, and the resulting signal would be choppy to virtually unreadable, especially at higher speeds, due to random delays on the IP link. If you transmit completed characters the theoretical minimum delay is one character, but the resulting signal would have unnatural gaps. To create a smooth transmission, you will need buffering that exceeds one character.
73, Ulrich, N2DE